view variant_effect_predictor/Bio/EnsEMBL/DBSQL/TranslationAdaptor.pm @ 3:d30fa12e4cc5 default tip

Merge heads 2:a5976b2dce6f and 1:09613ce8151e which were created as a result of a recently fixed bug.
author devteam <devteam@galaxyproject.org>
date Mon, 13 Jan 2014 10:38:30 -0500
parents 1f6dce3d34e0
children
line wrap: on
line source

=head1 LICENSE

  Copyright (c) 1999-2012 The European Bioinformatics Institute and
  Genome Research Limited.  All rights reserved.

  This software is distributed under a modified Apache license.
  For license details, please see

    http://www.ensembl.org/info/about/code_licence.html

=head1 CONTACT

  Please email comments or questions to the public Ensembl
  developers list at <dev@ensembl.org>.

  Questions may also be sent to the Ensembl help desk at
  <helpdesk@ensembl.org>.

=cut

=head1 NAME

Bio::EnsEMBL::DBSQL::TranslationAdaptor - Provides a means to fetch and store
Translation objects from a database.

=head1 DESCRIPTION

This adaptor provides a means to retrieve and store
Bio::EnsEMBL::Translation objects from/in a database.

Translation objects only truly make sense in the context of their
transcripts so the recommended means to retrieve Translations is
by retrieving the Transcript object first, and then fetching the
Translation.

=head1 SYNOPSIS

  use Bio::EnsEMBL::Registry;

  Bio::EnsEMBL::Registry->load_registry_from_db(
    -host => 'ensembldb.ensembl.org',
    -user => 'anonymous'
  );

  $transcript_adaptor =
    Bio::EnsEMBL::Registry->get_adaptor( "human", "core",
    "transcript" );

  $translation_adaptor =
    Bio::EnsEMBL::Registry->get_adaptor( "human", "core",
    "translation" );

  my $transcript = $transcript_adaptor->fetch_by_dbID(131243);
  my $translation =
    $translation_adaptor->fetch_by_Transcript($transcript);

  print("Translation Start Site: "
      . $translation->start_Exon()->stable_id() . " "
      . $translation->start()
      . "\n" );
  print("Translation Stop: "
      . $translation->end_Exon()->stable_id() . " "
      . $translation->end() );

=head1 METHODS

=cut

package Bio::EnsEMBL::DBSQL::TranslationAdaptor;

use vars qw(@ISA);
use strict;

use Bio::EnsEMBL::DBSQL::BaseAdaptor;
use Bio::EnsEMBL::Translation;
use Bio::EnsEMBL::Utils::Exception qw( throw warning deprecate );
use Bio::EnsEMBL::Utils::Scalar qw( assert_ref );


@ISA = qw( Bio::EnsEMBL::DBSQL::BaseAdaptor );

=head2 fetch_all_alternative_by_Transcript

  Arg [1]    : Bio::EnsEMBL::Transcript $transcript
  Example    :

    @tl = @{
      $translation_adaptor->fetch_all_alternative_by_Transcript(
                                                            $transcript)
      };

  Description: Retrieves all alternative translations associated with a
               particular transcript.  If no alternative translation is
               found, a reference to an empty list is returned.

  Returntype : listref of Bio::EnsEMBL::Translation
  Exceptions : throw on incorrect argument
  Caller     : Transcript
  Status     : Stable

=cut

sub fetch_all_alternative_by_Transcript {
  my ( $self, $transcript ) = @_;

  assert_ref($transcript, 'Bio::EnsEMBL::Transcript');

  my $tl_created_date =
    $self->db()->dbc()->from_date_to_seconds('tl.created_date');
  my $tl_modified_date =
    $self->db()->dbc()->from_date_to_seconds('tl.modified_date');

  my $sql =
    sprintf( "SELECT tl.translation_id, tl.start_exon_id, "
      . "tl.end_exon_id, tl.seq_start, tl.seq_end, "
      . "tl.stable_id, tl.version, %s, %s "
      . "FROM translation tl "
      . "JOIN transcript t "
      . "ON (t.transcript_id = tl.transcript_id) "
      . "WHERE tl.transcript_id = ? "
      . "AND tl.translation_id != t.canonical_translation_id",
    $tl_created_date, $tl_modified_date );

  my $transcript_id = $transcript->dbID();
  my $sth           = $self->prepare($sql);
  $sth->bind_param( 1, $transcript_id, SQL_INTEGER );

  $sth->execute();

  my (
    $translation_id, $start_exon_id, $end_exon_id,
    $seq_start,      $seq_end,       $stable_id,
    $version,        $created_date,  $modified_date
  );

  $sth->bind_columns(
    \(
      $translation_id, $start_exon_id, $end_exon_id,
      $seq_start,      $seq_end,       $stable_id,
      $version,        $created_date,  $modified_date
    ) );

  # Get all alternative translations.
  my $translations = [];
  while ( $sth->fetch() ) {
    if ( !defined($translation_id) ) { next }

    my ( $start_exon, $end_exon );

    # this will load all the exons whenever we load the translation
    # but I guess thats ok ....

    foreach my $exon ( @{ $transcript->get_all_Exons() } ) {
      if ( $exon->dbID() == $start_exon_id ) { $start_exon = $exon }
      if ( $exon->dbID() == $end_exon_id )   { $end_exon   = $exon }
    }

    if ( !( defined($start_exon) && defined($end_exon) ) ) {
      throw(
        sprintf(
          "Could not find start or end exon in transcript_id=%d\n",
          $transcript->dbID() ) );
    }

    my $translation =
      Bio::EnsEMBL::Translation->new_fast( {
                             'dbID'          => $translation_id,
                             'adaptor'       => $self,
                             'start'         => $seq_start,
                             'end'           => $seq_end,
                             'start_exon'    => $start_exon,
                             'end_exon'      => $end_exon,
                             'stable_id'     => $stable_id,
                             'version'       => $version,
                             'created_date'  => $created_date || undef,
                             'modified_date' => $modified_date || undef,
                           } );

    $translation->transcript($transcript);

    push( @{$translations}, $translation );

  } ## end while ( $sth->fetch() )

  return $translations;
} ## end sub fetch_all_by_Transcript

=head2 fetch_by_Transcript

  Arg [1]    : Bio::EnsEMBL::Transcript $transcript
  Example    : $tl = $translation_adaptor->fetch_by_Transcript($transcript);
  Description: Retrieves a Translation via its associated transcript.
               If the Translation is not found, undef is returned.
  Returntype : Bio::EnsEMBL::Translation
  Exceptions : throw on incorrect argument
  Caller     : Transcript
  Status     : Stable

=cut

sub fetch_by_Transcript {
  my ( $self, $transcript ) = @_;

  assert_ref( $transcript, 'Bio::EnsEMBL::Transcript' );

  my $tl_created_date =
    $self->db()->dbc()->from_date_to_seconds('tl.created_date');
  my $tl_modified_date =
    $self->db()->dbc()->from_date_to_seconds('tl.modified_date');

  my $sql =
    sprintf( "SELECT tl.translation_id, tl.start_exon_id, "
      . "tl.end_exon_id, tl.seq_start, tl.seq_end, "
      . "tl.stable_id, tl.version, %s, %s "
      . "FROM translation tl "
      . "JOIN transcript tr "
      . "ON (tl.translation_id = tr.canonical_translation_id) "
      . "WHERE tr.transcript_id = ?",
    $tl_created_date, $tl_modified_date );

  my $transcript_id = $transcript->dbID();
  my $sth           = $self->prepare($sql);
  $sth->bind_param( 1, $transcript_id, SQL_INTEGER );

  $sth->execute();

  my (
    $translation_id, $start_exon_id, $end_exon_id,
    $seq_start,      $seq_end,       $stable_id,
    $version,        $created_date,  $modified_date
  ) = $sth->fetchrow_array();
  $sth->finish();

  if ( !defined($translation_id) ) { return undef }

  my ( $start_exon, $end_exon );

  # this will load all the exons whenever we load the translation
  # but I guess thats ok ....

  foreach my $exon ( @{ $transcript->get_all_Exons() } ) {
    if ( $exon->dbID() == $start_exon_id ) { $start_exon = $exon }
    if ( $exon->dbID() == $end_exon_id )   { $end_exon   = $exon }
  }

  if ( !( defined($start_exon) && defined($end_exon) ) ) {
    throw(
      sprintf( "Could not find start or end exon in transcript_id=%d\n",
        $transcript->dbID() ) );
  }

  my $translation =
    Bio::EnsEMBL::Translation->new_fast( {
                             'dbID'          => $translation_id,
                             'adaptor'       => $self,
                             'start'         => $seq_start,
                             'end'           => $seq_end,
                             'start_exon'    => $start_exon,
                             'end_exon'      => $end_exon,
                             'stable_id'     => $stable_id,
                             'version'       => $version,
                             'created_date'  => $created_date || undef,
                             'modified_date' => $modified_date || undef,
                           } );

  $translation->transcript($transcript);

  return $translation;
} ## end sub fetch_by_Transcript



=head2 fetch_all_by_external_name

  Arg [1]    : string $external_name
               The external identifier for the translation(s) to be
               obtained.
  Arg [2]    : (optional) string $external_db_name
               The name of the external database from which the
               identifier originates.
  Arg [3]    : Boolean override. Force SQL regex matching for users
               who really do want to find all 'NM%'
  Example    : my @translations =
                  @{ $trl_adaptor->fetch_all_by_external_name('BRCA2') };
               my @many_translations = 
                  @{ $trl_adaptor->fetch_all_by_external_name('BRCA%') };
  Description: Retrieves a list of translations fetched via an
               external identifier.  Note that this may not be a
               particularly useful method, because translations
               do not make much sense out of the context of
               their transcript.  It may be better to use the
               TranscriptAdaptor::fetch_all_by_external_name instead.
               SQL wildcards % and _ are supported in the $external_name
               but their use is somewhat restricted for performance reasons.
               Users that really do want % and _ in the first three characters
               should use argument 3 to prevent optimisations
  Returntype : reference to a list of Translations
  Exceptions : none
  Caller     : general
  Status     : Medium Risk
             :   At some time may be deprecated to instead use 
             :   TranscriptAdaptor::fetch_all_by_external_name 

=cut

sub fetch_all_by_external_name {
  my ( $self, $external_name, $external_db_name, $override ) = @_;

  my $entry_adaptor = $self->db->get_DBEntryAdaptor();

  my @ids = $entry_adaptor->list_translation_ids_by_extids( 
            $external_name, $external_db_name, $override );

  my $transcript_adaptor = $self->db()->get_TranscriptAdaptor();

  my @out;
  foreach my $id (@ids) {
    my $transcript = $transcript_adaptor->fetch_by_translation_id($id);

    if ( defined($transcript) ) {
      push @out, $self->fetch_by_Transcript($transcript);
    }
  }

  return \@out;
}

=head2 fetch_all_by_GOTerm

  Arg [1]   : Bio::EnsEMBL::OntologyTerm
              The GO term for which translations should be fetched.

  Example:  @translations = @{
              $translation_adaptor->fetch_all_by_GOTerm(
                $go_adaptor->fetch_by_accession('GO:0030326') ) };

  Description   : Retrieves a list of translations that are
                  associated with the given GO term, or with any of
                  its descendent GO terms.

  Return type   : listref of Bio::EnsEMBL::Translation
  Exceptions    : Throws of argument is not a GO term
  Caller        : general
  Status        : Stable

=cut

sub fetch_all_by_GOTerm {
  my ( $self, $term ) = @_;

  assert_ref( $term, 'Bio::EnsEMBL::OntologyTerm' );
  if ( $term->ontology() ne 'GO' ) {
    throw('Argument is not a GO term');
  }

  my $entryAdaptor = $self->db->get_DBEntryAdaptor();

  my %unique_dbIDs;
  foreach my $accession ( map { $_->accession() }
                          ( $term, @{ $term->descendants() } ) )
  {
    my @ids =
      $entryAdaptor->list_translation_ids_by_extids( $accession, 'GO' );
    foreach my $dbID (@ids) { $unique_dbIDs{$dbID} = 1 }
  }

  my @result;
  if ( scalar( keys(%unique_dbIDs) ) > 0 ) {
    my $transcript_adaptor = $self->db()->get_TranscriptAdaptor();

    foreach my $dbID ( sort { $a <=> $b } keys(%unique_dbIDs) ) {
      my $transcript =
        $transcript_adaptor->fetch_by_translation_id($dbID);
      if ( defined($transcript) ) {
        push( @result, $self->fetch_by_Transcript($transcript) );
      }
    }
  }

  return \@result;
} ## end sub fetch_all_by_GOTerm

=head2 fetch_all_by_GOTerm_accession

  Arg [1]   : String
              The GO term accession for which genes should be
              fetched.

  Example   :

    @genes =
      @{ $gene_adaptor->fetch_all_by_GOTerm_accession('GO:0030326') };

  Description   : Retrieves a list of genes that are associated with
                  the given GO term, or with any of its descendent
                  GO terms.  The genes returned are in their native
                  coordinate system, i.e. in the coordinate system
                  in which they are stored in the database.  If
                  another coordinate system is required then the
                  Gene::transfer or Gene::transform method can be
                  used.

  Return type   : listref of Bio::EnsEMBL::Gene
  Exceptions    : Throws of argument is not a GO term accession
  Caller        : general
  Status        : Stable

=cut

sub fetch_all_by_GOTerm_accession {
  my ( $self, $accession ) = @_;

  if ( $accession !~ /^GO:/ ) {
    throw('Argument is not a GO term accession');
  }

  my $goAdaptor =
    Bio::EnsEMBL::Registry->get_adaptor( 'Multi', 'Ontology',
                                         'OntologyTerm' );

  my $term = $goAdaptor->fetch_by_accession($accession);

  return $self->fetch_all_by_GOTerm($term);
}

=head2 store

  Arg [1]    : Bio::EnsEMBL::Translation $translation
               The translation object to be stored in the database 
  Example    : $transl_id = $translation_adaptor->store($translation);
  Description: Stores a translation object in the database
  Returntype : int - the new dbID of the stored translation
  Exceptions : thrown if the dbID of the start_Exon or end_Exon is not 
               defined.
               thrown if only partial stable id information is present (e.g.
               identifier but not version number)
  Caller     : Transcript::store
  Status     : Stable

=cut

sub store {
  my ( $self, $translation, $transcript_id )  = @_;
  
  my $start_exon = $translation->start_Exon();
  my $end_exon   = $translation->end_Exon();
 
  if(!$start_exon) {
    throw("Translation must define a start_Exon to be stored.");
  }
 
  if(!$end_exon) {
    throw("Translation must define an end_Exon to be stored.");
  }
 
  if(!$start_exon->dbID) {
    throw("start_Exon must have a dbID for Translation to be stored.");
  }

  if(!$end_exon->dbID) {
    throw("end_Exon must have a dbID for Translation to be stored.");
  }

  my $store_translation_sql = qq(
         INSERT INTO translation 
             SET seq_start = ?, 
                 start_exon_id = ?,
                 seq_end = ?, 
                 end_exon_id = ?, 
                 transcript_id = ?
  );

  if (defined($translation->stable_id)) {
      my $created = $self->db->dbc->from_seconds_to_date($translation->created_date());
      my $modified = $self->db->dbc->from_seconds_to_date($translation->modified_date());
      $store_translation_sql .= ", stable_id = ?, version = ?, created_date = " . $created . " , modified_date = " . $modified;

  }

  my $sth = $self->prepare($store_translation_sql);
  $sth->bind_param(1,$translation->start,SQL_INTEGER);
  $sth->bind_param(2,$translation->start_Exon->dbID,SQL_INTEGER);
  $sth->bind_param(3,$translation->end,SQL_INTEGER);
  $sth->bind_param(4,$translation->end_Exon->dbID,SQL_INTEGER);
  $sth->bind_param(5,$transcript_id,SQL_INTEGER);


  if (defined($translation->stable_id)) {
 
    $sth->bind_param(6, $translation->stable_id,SQL_VARCHAR);
    my $version = ($translation->version()) ? $translation->version() : 1;
    $sth->bind_param(7, $version,SQL_VARCHAR);
  }

  $sth->execute();
 
  my $transl_dbID = $sth->{'mysql_insertid'};

  #
  # store object xref mappings to translations
  #
 
  my $dbEntryAdaptor = $self->db()->get_DBEntryAdaptor();
  # store each of the xrefs for this translation
  foreach my $dbl ( @{$translation->get_all_DBEntries} ) {
     $dbEntryAdaptor->store( $dbl, $transl_dbID, "Translation", 1 );
  }

  #storing the protein features associated with the translation
  my $pfadaptor = $self->db->get_ProteinFeatureAdaptor();
  foreach my $pf(@{$translation->get_all_ProteinFeatures}){
    $pfadaptor->store($pf, $transl_dbID);
  }

  $translation->get_all_Attributes();

  # store any translation attributes that are defined
  my $attr_adaptor = $self->db->get_AttributeAdaptor();
  $attr_adaptor->store_on_Translation($transl_dbID,
                                      $translation->get_all_Attributes());

  $translation->dbID($transl_dbID);
  $translation->adaptor($self);

  return $transl_dbID;
}



=head2 remove

  Arg [1]    : Bio::EnsEMBL::Translation $translation
  Example    : $translation_adaptor->remove($translation);
  Description: Removes a translation completely from the database, and all
               associated information including protein features etc.
  Returntype : none
  Exceptions : throw on incorrect arguments
               warning if translation is not in this database
  Caller     : TranscriptAdaptor::remove
  Status     : Stable

=cut

sub remove {
  my $self = shift;
  my $translation = shift;

  if(!ref($translation) || !$translation->isa('Bio::EnsEMBL::Translation')) {
    throw("Bio::EnsEMBL::Translation argument expected.");
  }

  if( !$translation->is_stored($self->db()) ) {
    warning("Cannot remove translation " . $translation->dbID() . 
            ". Is not stored in this database.");
    return;
  }

  # remove athe attributes associated with this translation
  my $attrib_adp = $self->db->get_AttributeAdaptor;
  $attrib_adp->remove_from_Translation($translation);

  # remove all xref associations to this translation
  my $dbe_adaptor = $self->db()->get_DBEntryAdaptor();
  foreach my $dbe (@{$translation->get_all_DBEntries()}) {
    $dbe_adaptor->remove_from_object($dbe, $translation, 'Translation');
  }

  # remove all protein_features on this translation
  my $sth = $self->prepare
    ("DELETE FROM protein_feature WHERE translation_id = ?");
  $sth->bind_param(1,$translation->dbID,SQL_INTEGER);
  $sth->execute();
  $sth->finish();

  # remove the translation itself

  $sth = $self->prepare("DELETE FROM translation WHERE translation_id = ?" );
  $sth->bind_param(1,$translation->dbID,SQL_INTEGER);
  $sth->execute();
  $sth->finish();

  $translation->dbID( undef );
  $translation->adaptor(undef);

  return
}


=head2 list_dbIDs

  Arg [1]    : none
  Example    : @translation_ids = @{$translation_adaptor->list_dbIDs()};
  Description: Gets an array of internal ids for all translations in the current db
  Returntype : list of ints
  Exceptions : none
  Caller     : ?
  Status     : Stable

=cut

sub list_dbIDs {
   my ($self) = @_;

   return $self->_list_dbIDs("translation");
}


=head2 list_stable_ids

  Arg [1]    : none
  Example    : @transl_stable_ids = @{$transl_adaptor->list_stable_dbIDs()};
  Description: Gets an array of stable ids for all translations in the current 
               db
  Returntype : reference to a list of strings
  Exceptions : none
  Caller     : general
  Status     : Stable

=cut

sub list_stable_ids {
   my ($self) = @_;

   return $self->_list_dbIDs("translation", "stable_id");
}



=head2 fetch_by_dbID

  Arg [1]    : int $dbID
               The internal identifier of the Translation to obtain
  Example    : $translation = $translation_adaptor->fetch_by_dbID(1234);
  Description: This fetches a Translation object via its internal id.
               This is only debatably useful since translations do
               not make much sense outside of the context of their
               Transcript.  Consider using fetch_by_Transcript instead.
  Returntype : Bio::EnsEMBL::Translation, or undef if the translation is not
               found.
  Exceptions : warning if an additional (old style) Transcript argument is
               provided
  Caller     : ?
  Status     : Stable

=cut

sub fetch_by_dbID {
  my ( $self, $dbID, $transcript ) = @_;

  if ($transcript) {
    deprecate(   "Use of fetch_by_dbID "
               . "with a Transcript argument is deprecated."
               . "Use fetch_by_Transcript instead." );
  }

  if ( !defined($dbID) ) {
    throw("dbID argument is required");
  }

  my $transcript_adaptor = $self->db()->get_TranscriptAdaptor();
  $transcript = $transcript_adaptor->fetch_by_translation_id($dbID);

  if ( defined($transcript) ) {
    my $translation = $self->fetch_by_Transcript($transcript);

    if ( defined($translation) && $translation->dbID()==$dbID ) {
      return $translation;
    }

    my @alt_translations =
      @{ $self->fetch_all_alternative_by_Transcript($transcript) };

    foreach my $alt_translation (@alt_translations) {
      if ( $alt_translation->dbID() == $dbID ) {
        return $alt_translation;
      }
    }
  }

  return undef;
} ## end sub fetch_by_dbID


=head2 fetch_by_stable_id

  Arg [1]    : string $stable_id
               The stable identifier of the Translation to obtain
  Example    : $translation = $translation_adaptor->fetch_by_stable_id("ENSP00001");
  Description: This fetches a Translation object via its stable id.
               This is only debatably useful since translations do
               not make much sense outside of the context of their
               Transcript.  Consider using fetch_by_Transcript instead.
  Returntype : Bio::EnsEMBL::Translation or undef if the translation is not
               found.
  Exceptions : warning if an additional (old style) Transcript argument is
               provided
  Caller     : ?
  Status     : Stable

=cut

sub fetch_by_stable_id {
   my ($self,$stable_id) = @_;

   if(!$stable_id) {
     throw("stable id argument is required");
   }

   my $transcript_adaptor = $self->db()->get_TranscriptAdaptor();
   my $transcript = 
     $transcript_adaptor->fetch_by_translation_stable_id($stable_id);

   return undef if(!$transcript);

   return $self->fetch_by_Transcript($transcript);
}


=head2 fetch_all_by_Transcript_list

  Arg [1]    : reference to list of Bio::EnsEMBL::Transcripts $transcripts
               The list of $transcripts to obtain Translation object for.
  Example    : @translations = @{$tla->fetch_all_by_Transcript_list([$t1,$t2]);
  Description: Fetches all translations associated with the list of transcripts
               passed to this method.  The passed transcripts will also have
               their translation set by this method.
  Returntype : Reference to list of Bio::EnsEMBL::Translations
  Exceptions : None
  Caller     : general
  Status     : Stable

=cut

sub fetch_all_by_Transcript_list {
  my ($self,$transcripts) = @_;

  if(!defined($transcripts) || ref($transcripts) ne 'ARRAY') {
    throw("reference to list of Transcripts argument is required");
  }

  return [] if(!@$transcripts);

  my %trans_hash = map {$_->dbID() => $_} @$transcripts;
  my @id_list = keys %trans_hash;

  my @out;

  # mysql is faster and we ensure that we do not exceed the max query size by
  # splitting large queries into smaller queries of 200 ids
  my $max_size = 200;

  my ( $transcript_id, $translation_id, $start_exon_id, $end_exon_id,
       $seq_start, $seq_end, $stable_id, $version, 
       $created_date, $modified_date );

  my %ex_hash;

  while(@id_list) {
    my @ids;
    if(@id_list > $max_size) {
      @ids = splice(@id_list, 0, $max_size);
    } else {
      @ids = splice(@id_list, 0);
    }

    my $id_str;
    if(@ids > 1)  {
      $id_str = " IN (" . join(',', @ids). ")";
    } else {
      $id_str = " = " . $ids[0];
    }
    
    my $canonical_lookup = $self->dbc()->sql_helper()->execute_into_hash(
      -SQL => 'SELECT transcript_id, canonical_translation_id FROM transcript WHERE transcript_id '.$id_str
    );

    my $created_date = $self->db->dbc->from_date_to_seconds("tl.created_date");
    my $modified_date = $self->db->dbc->from_date_to_seconds("tl.modified_date");

    my $sth = $self->prepare
      ("SELECT tl.transcript_id, tl.translation_id, tl.start_exon_id,
           tl.end_exon_id, tl.seq_start, tl.seq_end,
           tl.stable_id, tl.version, " . $created_date . "," .
       $modified_date . 
       " FROM translation tl
         WHERE tl.transcript_id $id_str");

    $sth->execute();

    $sth->bind_columns( \$transcript_id, \$translation_id, \$start_exon_id, \$end_exon_id,
                        \$seq_start, \$seq_end, \$stable_id, \$version,
			\$created_date, \$modified_date );

    while($sth->fetch()) {
      my ($start_exon, $end_exon);

      # this will load all the exons whenever we load the translation
      # but I guess thats ok ....

      my $tr = $trans_hash{$transcript_id};

      foreach my $exon (@{$tr->get_all_Exons()}) {
        if(!$start_exon && $exon->dbID() == $start_exon_id ) {
          $start_exon = $exon;
          last if($end_exon);
        }

        if(!$end_exon && $exon->dbID() == $end_exon_id ) {
          $end_exon = $exon;
          last if($start_exon);
        }
      }

      unless($start_exon && $end_exon) {
        throw("Could not find start or end exon in transcript\n");
      }

      my $tl =  Bio::EnsEMBL::Translation->new
        (-dbID => $translation_id,
         -seq_start => $seq_start,
         -seq_end => $seq_end,
         -start_exon => $start_exon,
         -end_exon => $end_exon,
         -stable_id => $stable_id,
         -version => $version,
	 -created_date => $created_date || undef,
	 -modified_date => $modified_date || undef);
      
      $tl->adaptor($self);
      my $canonical_translation_id = $canonical_lookup->{$transcript_id};
      $tr->translation($tl) if $translation_id == $canonical_translation_id;

      push @out, $tl;
    }
  }

  return \@out;
}



=head2 fetch_all_by_DBEntry

  Description: DEPRECATED, this has been renames fetch_all_by_external_name

=cut

sub fetch_all_by_DBEntry {
  my $self = shift;
  deprecate("Use fetch_all_by_external_name instead.");
  return $self->fetch_all_by_external_name(@_);
}

=head2 get_stable_entry_info

 Description: DEPRECATED - This method should no longer be needed. Stable
              id info is fetched when the transcript is.

=cut

sub get_stable_entry_info {
  my ($self,$translation) = @_;

  deprecate( "This method shouldnt be necessary any more" );

  unless(defined $translation && ref $translation && 
	 $translation->isa('Bio::EnsEMBL::Translation') ) {
    throw("Needs a Translation object, not a [$translation]");
  }

  my $sth = $self->prepare("SELECT stable_id, version 
                            FROM   translation
                            WHERE  translation_id = ?");
  $sth->bind_param(1,$translation->dbID,SQL_INTEGER);
  $sth->execute();

  my @array = $sth->fetchrow_array();
  $translation->{'_stable_id'} = $array[0];
  $translation->{'_version'}   = $array[1];

  return 1;
}

=head2 fetch_all

  Example     : $translations = $translation_adaptor->fetch_all();
  Description : Retrieves all canonical and alternative translations 
                stored in the database.
  Returntype  : listref of Bio::EnsEMBL::Translation
  Caller      : general
  Status      : At Risk

=cut

sub fetch_all {
  my ($self) = @_;
  my $transcript_adaptor = $self->db()->get_TranscriptAdaptor();

  my @translations;
  foreach my $transcript (@{$transcript_adaptor->fetch_all}) {
     my $translation = $self->fetch_by_Transcript($transcript);
     if ($translation) {
	 push @translations, $translation;
     }
     foreach my $alt_translation (@{$self->fetch_all_alternative_by_Transcript($transcript)}) {
	 push @translations, $alt_translation;
     }
  }
  return \@translations;
}

1;